I'll be the dissenter here. I love my 4-jaw scroll chuck (Bison, Poland) bought about ten years ago. I already had 3-jaw scroll, 4-jaw independent, and Sjogren 5C collet chuck. It stays on the lathe most of the time. Yes you can hold hex in it, just don't gorilla the wrench, 'cause it side loads the jaws. Mine is still within a thou centering and repeatability (on od ground stock). My next most used chuck is the 4-jaw independent, then comes the 3-jaw which I've pretty well dedicated to soft jaws. Haven't had the collet chuck on the machine in so long, I can't remember the last time. I used to use 5C square collets with it, and that was handy, but don't have the need anymore with the 4-jaw scroll. I've also got soft top jaws for the 4-jaw scroll, and a neat feature is that you can remove the top jaws, and install only two top soft jaws, and get the function of a 2-jaw scroll chuck. All in all, it's a very versatile chuck, and I wouldn't be without it!
That said, I agree that order of purchase should be 4-jaw independent, 3-jaw scroll (and soft jaws!), then the 4-jaw scroll.
Regards
Bob